<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			.demo{
				width: 100px;
				height: 100px;
			}
			.demo1{
				background: #007AFF;
			}
			.demo2{
				background: #2AC845;
			}
		</style>
	</head>
	<body>
		<div class="demo demo1"></div>
		<div class="demo demo2"></div>
		<script src="jquery-3.4.1.js"></script>
		<script type="text/javascript">
			// console.log($('.demo'))
			$('.demo').click(function(){
				console.log("点击 ")
			})
		</script>
	</body>
</html>
